Automatic feed control



E. R. RAMSEY AND A L. BLOMFIELD.

AUTOMATIC FEED CONTROL.

v APPLICATION FILED APR=5,1919. I 1,413,934. Patented Apr- 25, 1922.

3 SHEETS-SHEET L INVENTORS.

[LMER R RAMSEY/W0 A. L 54 OMF/ALD.

A TTORNE Y.

E. R. RAMSEY AND A. L. BLOMFIELD.

AUTOMATIC FEED CONTROL. APPLICATION FILED APR. 5, 1919.

P atent d Apr. 25, 1922.

3 SHEETS SHEET 2.

INVENTOR. [L ME)? A. fiAMsgm/p A BLOMF'I/E'LD.

E. R. RAMSEY AND A. L. BL OMFIELD.

AUTOMATIC FEED CONTROL.

APPLICATION FILED APR=5,1919.

3 SHEETS-SHEET 3.

Patented Apr. 25, 1922.

I INVENTORS.

[LMER ff. Rwy/55y AND ver, in the county of ELMER R. RAMSEY, DENVER, AND ALF COLORADO, ASS-IGNORE} TO THE norm RATION or DELAWARE.

PATEN T oer-Ice.

RED L. BLOMFIELD, 0F COIIORADO SPRINGS,

COMPANY, OF NEW YORK. N, Y.,, A CORPO- AUTOMATIC FEED CCNTROL.

To all whom it may concern Y 4 e it known that we, ELMER R. RAMSEY and United States, residing, respectively, at Denenver and State of Colorado, and at Colorado Springs, in the county of El aso and State of Colorado, have invented certain new and useful Improvements in Automatic Feed Controls, of which the following is a specification.

hisvinvention relates to a method of automatically regulating the feed of granular material to apparatus other liquid.

ur invention is to grinding systems in which unlformity in the quantity and consistency of the load is essential to a constant maxim-um efiiciency in operation.

Our improved method of feed control has been shown 1n the h receives the product of the mill and returns the oversize thereto for further comminution. w Q

The weight of the load, which regulates the-feed, may be utilized before the material enters the classifier, while it is being classified, or before it is returned to the mill for further grinding. In the first two instances the weight of the entire circulating load controls the feed to the grinding mill and under: the last mentioned condition the weight of only the oversize discharged from theclassifier for that purpose."v

, however, that even Sp: cification of Letters Patent. Anvlication filed April 5,

LFRED L. BLOMFIELD, citizens of the weight of'the oversize particularly applicable ga scoop Patented Apr. 25, 1922. 1919. Serial No. 287,905.

in the quantity of the coarser constituents of the load that the controlling function is performed.

system of cooperative devices for produclng the desired results under each of the above stated conditions has been illustrated in the drawings in which igure 1 represents the system as it is used tem by the weight enters the classifier;

igure 2, the system as employed in control ing the feed by variations in the weight of the circulating load within the classifier, and,

Figure 3, the system as adapted for use in regulating the feed by variations in the classifier, before it reenters the mill;

Figure 4 is a sectional elevation of the valve which controls the supply of liquid to the material under treatment, in its. normal condition.

We desire it understood that the system of cooperative devices shown in the drawings is connection'with a grinding m1ll operating either separately or in circuit with a classifier. i

It should furthermore be understood that in using the terms material and load in the following description, reference ishad to both dry solids and solids in liquid and that the means for automatically regulating a supply of a liquid to the circulating mate rial may if so desired be employed without the means for regulating the feed of. solids, to constantly maintain the'ciroulating load at a determinate degree of density.

Referring firstto Figure lof the drawings, the reference ball grinding mill ,the mill dlps intermittently intoa feedtrough 4 and discharges its load into the inlet opening with which-it is connected.

discharged from the numeral 2 designates a having at its intake end 3 which in the rotary movement of 'the circuit of the motor,

and empties into the The ground at where the material is conveyed to a classifier 7 of suitable construction by means of chute 8.

The classifier operates to divide the fine solids in the product of the mill from the oversize which is separately from the classifier and conducted by a chute 9 to the feed trough 1 to be returned to the mill for further grinding.

The fresh material is fed to the trough by an endless belt 10 which receives its load from a superposed supply bin 12. The belt is mounted upon rotating rollers 13 and 14 one of which is driven by connection with an electric motor 15.

The elevator 6 is suspended from the short arm of a lever 16, fulcrumed'as at 17, the opposite long arm of a link 18 connected with second lever point 20.

A spring 21 fixed at its lower end and connected with the long arm of the first lever compensates for the weight of the elevator and its load under normal conditions, and by opposing the force'of gravitation acting upon the short arm of the lever yieldingly maintains its equilibrium.

The arm 22' of the lever 19 constitutes the controlling member of a rheostat 23 by which a variable resistance is introduced into which in the construction shown in the drawings includes a source of electricity negative conductors 25 and 26 The opposite arm of the lever is through the medium of a linkU27connected with a crank 28 on valve 29 of the butterfly the flow of liquids which connects with disposed source of. suppl feed trough of the mil In the operation of the above-described system, the feed belt conveys the material discharged from the supply-bin 8 continuously to the feed trough of the rinding mill and the valve 29 is in a partial y open position as shown in Figure 4 to continuously supply a certain quantity of water to the material under treatment. An increase in the amount of material discharged from the mill during a determined period of opera- ,t-ion will cause the short arm of the lever 16 to move downwardlyagainst the action of the spring 21 by the pro I creased weight of the load'o the elevator.

The consequently upwardly arm of the lever. aotin upon can the short arm of a 19 which has its fulcrum at a the rotary plug of a type whichthrough a conduit 30 a conveniently the lever 19',

which is by means of 24 and positive and" ortionately inmoving long ses theivalve to iurt er open'and thereby increasethe supply of water to the feedtrough of the mill, and at the same time increases the resistance in the rheostat to reduce the velocity of the motor and of the therewith connected feed-belt.

The increased supply of liquid to the trough tends to immediately correct any 1 ferences in the operation of the mill and any retardation in the circulatory movement of the load by an overaccumulation of solid matter and by subsequentlydecreasing the feed of fresh material to the mill, the system is rapidly restored to its normal condition when by the decrease in weight of the load of the elevator, the levers and the therewith connected elements of the system are returned to their original positlon.

In case the quantity of material in'the mill falls below its capacity, the proportionate decrease in weight of the load of the elevator causes the levers to move in the opposite irection with the result that by a resistance to the current flow in the rheostat, the movement of the feed-belt is accelerated until the normal amount of material passes through the mill,- while, at the same time the water supplied to the mill is diminished by a closing movement of the valve.

It will thus be seen that by automatically controllin thefeed and the water supply to the mil by variations in the weight 0 all or part of the circulating load, the mill and the classifier in circuit caused to constantly operate with a maximum efiiciency, loss of energy is in consequence avoided, a uniform movement of material' through the circuit is maintained and wear on the grinding elements of the mill improportionate to the amount of energy ex ended, is eliminated.

n the construction shown in Figure 2, the before-stated results are obtainedby weighing the circulating load while it is containe in the classifier for the separation of its fines from the coarse material or oversize.

The classifier is'pivotally supported at one of its ends, as at-31, an its opposite end rests upon the short arm of which by means of the link 18 is connecte with the short arm of the second lever 19 whose longarni is by-the link 27 connected with the crank-arm 28'of the rotating lug of thevalve 29;;and serves as the contro ling medium of the rheostat 23.

An increase or decrease in the weightof the material in the classifier causes it to move about its fulcrum and thereby actuates the levers which control the supply 0 liquid through the .conduit 30- and the supply of fresh material by the movement of the feed belt as in the first described invention.

. In Figure 3, of the drawings, and water supply are controlled t of the ooarse p decrease o1 therewith are the lever 16 form of the the feed roduct terminate period enters the grinding ion thereof is though trolled by th of the classifier discharged during a deof operation before it remill. v

The oversize discharged from the classifier is by the chute 9 delivered onto an endless belt 32 which carries it to the feed trough of the mill. 7

The belt is mounted on rollers 33 and 34 one of which is supported in stationary bearings 35 and the other one of which is mounted in boxes 36 which are suspended from the short arm of the lever 16 by a link 37 1 The spring 21 acts upon the same arm of the lever to compensate for the weight of the belt and its normal load as in the first described form of the invention.

The long arm of the lever is by a link 38 connected with the crank arm of the valve and also carries a contact which constitutes the controlling medium of the rheostat.

The'operation of" the system by a decrease or increase in the weight of the overh size of the classifier belt 32 is identical to our invention in which mill and the contents of actuating mediums and discharged 'onto the that ofthe forms of the discharge of the the classifier are the no further descripto be necessary at is point.

at We claim and desire to secure by Letters-Patent is: v

1. In combination, a grinding mill, a feed supply and a water supply discharging into the mill, a receptacle and a weighing device for the products of said mill, and means controlled by the movement of the Weighing device for regulating the quantity of material and watersupplied to the mill by said feed and water supplies respectively.

2. In combination, a grinding mill, a feed supply and a water supply discharging into the mill, a weighing device, and means cone movement of the weighing device for regulatin the quantity of water and material to the mill.

3. In combination, a grinding mill, a feed f V supply for the mill, a receptacle and a weighmg device for the products of said mill means controlled by th Weighing mechanism quantity of material fed to the In combination, a grinding mill, a feed supply for said mill, a valve controlled liquid supply, a receptacle and a weighing and mill.

device for the products of said mill, and s means controlled by the movement weighing device for regulating the of material fed to the mill and for a the valve to regulate simultaneo liquid supply.

5. In combination, a grinding mill, a feed supply for said mill, a valve controlled liquid supply, a receptaclev and a weighing device for the products of said mill, and means of the uantity j ustin li\sly the e movement of the b for regulating the controlled by the movement of the weighing device for adjusting the valve of the liquid supply to regulate the'latter.

In combination, a grinding mill, mechanism for feeding material to the mill, a receptacle and a Weighing device for the products of the mill, and means controlled by the movement of the Weighing device for regulating the feedingjmechanism.

In combination, a grinding mill, mechanism for feeding material thereto, a valve controlled liquid supply, a receptacle and a weighing device for the products of the mill,

and means controlled by the movement of the weighing device for operating the valve to regulate the liquid supply.

8. In combination, a grinding mill, mecha nism for feeding material to the mill, means for actuating the said mechanism including a closed electrical circuit, a device arranged in said circuit for varying the s'tren th of the current and the consequent feeding of .t e material to the mill, aweighing device for the products of the mill, a liquid supply, and means actuated by the movement of the 90 weighing device for controlling the liquid supply and having one of its members operating the current controlling device.

9. In combination, a grinding miIL-mechanism for feeding material to the mill, means for actuating the said mechanism including a closed electrical circuit, a device arranged in said circuit for varying the strength of the current and the consequent feeding of material to the. mil a Weighing device for the products of the mill, a liquid supply, and means actuated by th supply and means actuated he movement of the weighing device and connected with the valve of the liquid supply to regulate the same and having one of its members operatingthe current controlling device.

11. In combination, a grinding mill, a feed upply and a liquid supply for said mill, a weighing device or the products of the mill, a conveyor connected with the weighing deg vice and arranged to receive the products of the mill, and means controlled by the move- 125 ment of said weighing device for regulating the quantity of material and liquid supplied to the mill by said feed and liquid supplies respectively. 7

12. In combination, a. grinding mill, a feed130 controlled by supply and a liquid supply for said mill, a receptacle and a weighing device for the having a motor, a weighing device for the products of said mill, a closed circuit having the said motor arranged therein, a rheostat arranged in the said circuit, a liquid supply and means actuated by the weighing device and connected with the liquid supply and the rheostat for controlling the same.

In testimony whereof we have affixed our signatures.

' R. RAMSEY.

ELMER ALFRED L. BLOMFIELD. 

